Electrochemical fuel cells are generally known in the art and convert fuel and an oxidant to electricity. One such fuel cell is a solid polymer electrochemical cell and includes a membrane electrode assembly “MEA” that includes an ion exchange membrane or other electrolyte disposed between an anode and cathode. The MEA may include a catalyst or other catalytic material at each interface between the membrane and electrode to induce a desired electrochemical reaction. The electrodes are electrically coupled to provide a circuit for conducting electrons between the electrodes through an external circuit.
In a hydrogen powered fuel cell, hydrogen and air are supplied to electrodes on either side of an ion exchange membrane. Hydrogen is typically supplied to the anode where a catalyst promotes a separation into protons and electrons which are conducted through the external circuit. On the opposing side of the membrane, air is provided to the cathode where oxygen in the air reacts with the protons passing through the ion exchange membrane to produce byproduct water.
The fuel source in such hydrogen powered systems is flammable and should be monitored closely to prevent a dangerous condition. Examples are known in the art of providing hydrogen sensors in a fuel cell to monitor the hydrogen concentration and shut down or otherwise warn an operator of the fuel cell of the dangerous hydrogen concentration.
However, hydrogen sensors utilized to detect the concentration of a hydrogen fuel require a minimum presence of oxygen at the sensor location in order to detect the hydrogen concentration. If the hydrogen concentration at the sensor location is great enough to reduce the oxygen concentration below a required level to accurately detect hydrogen, the concentration of hydrogen detected by the sensor could be less than the actual hydrogen concentration at the sensor location. This situation may be described as sensor saturation.
There is therefore a need in the art for an improved method of detecting a hydrogen leak in a fuel cell that prevents false hydrogen concentration readings as a result of sensor saturation. There is also a need in the art for an improved method of detecting a hydrogen leak in a fuel cell that detects a hydrogen concentration before sensor saturation provides a false hydrogen concentration reading.